1. Field
The present application relates generally to the field of micro-structures, and, more particularly, to adhesive micro-structures.
2. Description of the Related Art
A natural adhesive system found in geckos is composed of micro-sized stalks (setae) that branch out into 100-1000 nano-sized branches (spatulae). At the end of these branches is a thin plate where adhesion to an opposing surface occurs through van der Waals forces, either by dispersion forces (Autumn K, et al. “Evidence for van der Waals adhesion in gecko setae,” PNAS 99, pp. 12252-12256 (2002), which is incorporated herein by reference in its entirety for all purposes), or by hydrogen bonding (Huber G, et al. “Evidence for capillarity contributions to gecko adhesion from single spatula nanomechanical measurements,” PNAS 1-2, 16293-16296 (2005), which is incorporated herein by reference in its entirety for all purposes). Microfabricating adhesive nano-fibers mimicking gecko foot-hair have been previously patented, see U.S. Pat. No. 6,872,439 and U.S. Pat. No. 6,737,160, each of which is hereby incorporated by reference in its entirety for all purposes. Like the wall climbing gecko, these microfabricated nano-fiber arrays have the ability to attach and detach to opposing substrates.